Today, Optus has announced it has updated its bring-your-own phone plans – reducing them to three plans, two of which are month-to-month plans (meaning that you are not tied to a contract); and now gives those on these plans access to its 4G network.

The $20 Optus SIM Plan and the $40 Optus SIM Plan are the month-to-month plans, meaning that you can cancel at any time without being charged a fee. The $20 plan offers $200 of “included value” – which includes phone calls to Australian numbers and all text messages. The $40 plan has an “included value” of $500, but you get unlimited standard SMS messages (if you send that to an Australian number).

The $60 Optus SIM Plan is the one that ties you to a 12 month contract. However it is the most attractive one in terms of what Optus gives you as “included value” – unlimited national voice calls to Australian numbers, unlimited SMS and MMS messages (to Australian numbers), and unlimited calls to your voicemail (other plans charge 90c per minute every time you access your voicemail).

I should stress that the $60 plan is an “introductory offer” – this ends on June 30 (or earlier, whenever Optus wants to pull it). Once that offer is done, it will be $65 per month.

On data – the $20 plan has a data allowance of 200MB; the $40 plan gives you 1GB of data; and the $60 plan offers 2GB of data. Excess data charges for all three plans are 25c per MB.